Photochemical chlorination of hydrocarbons



Nov. 2L E9@ E. L. HUMPHREY ETAL 253599 `pHoTocHxemfxIcm. cHLoRINATIoN oF HYDRocARBoNs Filed Sept. 24, 1948 Patented Nov. 21, 1950 Y2,530,699 ICE PHOTOCHEMICAL CHLORINATION F HYDRO CARBON S Earl L. Humphrey and Edward Mitchell, Pittse burgh, Pa., assignors to Gul! Research t Development Company, Pittsburgh, Pa., a corporation of Delaware Application September 24, 1948, Serial No. 51,034

9 Claims. (Cl. .2M-163) This invention relates to a process of chlorinating hydrocarbons, and more particularly to a process of photocatalytically chlorinating an industrial mixture of hydrocarbons such as a liquid petroleum fraction to a high chlorine content.

It has previously been proposed to accomplish photoeatalytic chlorination of petroleum fractions, but in general such operations have involved the introduction into the hydrocarbons of a relatively small percentage of chlorine.' The addition of a large percentage of chlorine has presented diiliculties because as the chlorine content of the mixture increases, the ability of the mixture to absorb chlorineis reduced and product decomposition occurs so that as a practical matter additional eil'ective chlorination is not accomplished by conventional procedures.

In accordance with the present invention, industrial mixtures of hydrocarbons such as liquid petroleum fractions are emciently chlorinated to a high chlorine content by intimately contacting 'the hydrocarbons with chlorine in the presence of active light rays, subjecting the partially chlorinated hydrocarbon mixture to the action of a solid adsorbent, and then intimately contacting the mixture with chlorine in the presence of light to accomplish additional chlorination. We have 'found that by practicing this process a petroleum fraction can be effectively chlorinated to a chlorine content of 70 per cent or more by weight in a relativly short time and with the use of simple equipment. Y

The hydrocarbon mixtures that may advantageously be chlorinated by the present process include light liquid petroleum fractions such as gasoline and kerosene fractions. The fractions may boil ovel a relatively wide temperature range. such as 300 F. or more between the initial and final boiling points, but for most purposes somewhat narrower boiling range fractions are more valuable. Thus a fraction having a boiling point range of from about to about 100 F.

f may be chlorinated to yield especially useful chlorinated compounds. 'lge process may also be used with value for the c urination of heavier petroleum fractions, such as lubricating oil fractions, but the extent of Achlorination easily attained is not as 4great as in the cases of the lighter fractions. Other hydrocarbon mixtures, such as light coal tar oils and the like, may be chlorinated effectively. The process may also be applied to the chlorination of relatively pure hydrocarbons. In the chlorination of such hydrocarbons, the process frequently has the advantage of materially reducing the time required for maximum chlorination. Pure hydrocarbons may usually be lchlorinated `effectively by conventional procedures. and therefore the degree ci' improvement may not be sufncient to 'justify use ofthe present process. However, there .is usually an important advantage when the hydrocarbon being chlorinated is a technical grade material which may be only to 95 kper cent pure. Y

In the chlorination of a liquid petroleum fraction by conventional photocatalytc procedures the acceptance of chlorine continues with a progressive coloring or darkening of the solution which appears to proceed 'so long as the chlorine is introduced under conditions causing acceptance of the chlorine by the hydrocarbons. Under such conditions there is a relatively low limit to the amount of chlorine that the mixture will absorb without concomitant product decomposition. 4

While the invention is not limited tc any theory of operation, we have reason to believe that during the initial stages of conventional chlorination, condensation or polymerization of unstable compounds in the mixture is effected and that the resulting polymers adversely affect the chlorination and also tend to induce continuing condensation or polymerization in the mixture throughout the chlorination. Thus, the diiilculty of chlorinating is continuously increased. We have discovered that by treating the partially chlorinated mixture with a. solid adsorbent the mixture obtained may be chlorinated to a high chlorine content while avoiding the indicated decomposition or condensation and polymerization of constituents of the mixture. For example, while in the initial stages darkening or coloring of the mixture takes place, after the adsorption treatment the mixture is capable of absorbing additional quantities "of chlorine in a relatively short period of time, and, even though the chlorine content of the mixture is increased to a high value, the mixture remains substantially clear and free from any color other than that due t0 the chlorinated compounds themselves.

The present process may be carried out in various ways. In accordance with one manner of proceeding, the hydrocarbon mixture is introduced into a vessel provided with a source of violet or ultra-violet rays or related short wave light rays of about 2000 to 5000 A. units. The vessel is also provided with a dispersing device for chlorine, this device being placed in the lower portion of the vessel. The pressure in the vessel is preferably maintained at about the pressure of the atmosphere and where the initial boiling point of the petroleum fraction is above the maximum temperature reached during the initial part of chlorination no special precautions need be taken regarding evolution of vapors. In cases where a relatively light fraction is subjected to chlorination, the pressure may be atmospheric or other pressure at which vapors o! the mixture are evolved but. in these cases thc reaction vessel should be provided with a reflux condenser in which theyapors are condensed ,and returned to the vessel. Alternatively, the pres- .3 sure may be maintained sufllciently high so that the initial boiling point of the fraction at the pressure in question is above the maximum chlorination temperature. The vessel is provided with heating means and may also be provided with cooling means, although we have found the latter not to be necessary if the rate of chlorine addition is controlled.

The introduction of chlorine through the dispersing device is preferably begun at a rate such that the exothermic reaction involved in the chlorination of the hydrocarbons is not sui'iicient to raise the temperature of the mixture above about 125 C.: the temperature preferably is between about 80 and 110 C. The rate of introduction of chlorine is generally such that only a very small amount of unreacted chlorine passes through the mixture, and it is preferred to con tinue the introduction of chlorine until a major reduction in the rate at which the chlorine is being accepted is noticed. At this stage the partially chlorinated mixture may contain about 35 to 45 per cent chlorine by weight.

The mixture is then removed from the vessel and may be passed through a body of a solid adsorbent in the form of granules; for exampleV 20 to 4v mesh particles. Alternatively, the mixture may be mixed with the adsorbent in ilnely divided form and then filtered. The solid adsorbent may be, for example. an activated carbon, or an activated clay such as an acid treated montmorillonite clay. The activated clay of this type marketed under the trade name Super Filtrol" is excellent for the purpose. When using fresh Super Filtrol" it has been found that r eilective treatment is accomplished when 1 to 2 volumes of clay are employed for 20 volumes of the chlorinated mixture. It will be understood that other solid adsorbents may be used, among which fullers earths and high surface area inorganic gels may be mentioned as examples. No particular precautions need be taken with respect to the adsorbent. For example, the adsorbent clay for use may be stored in contact with the atmosphere and contain several per cent adsorbed moisture. The advantageous results obtained do not appear to be dependent in any important respect upon a drying or dehydrating action of the adsorbent.

After treatment with the adsorbent the mixture is returned to the vessel in which the initial stages of chlorination were carried out and the introduction of chlorine is started.A At the beginning of the second stage of chlorination the exothermic reaction may be suillcient to maintain a satisfactory chlorination temperature or heating may be necessary. In any case, as the mixture becomes more heavily chlorinated, the reaction rate will begin to slow down. At this time the temperature of the mixture should be raised. This may be done gradually over the period of time required to accomplish the desired amount of chlorination or the temperature may be quickly raised to the maximum and maintained at that point. Thus the temperature during this second stage may vary from about 70 to 200 C.. preferably from about 110 to about 130 to 170 C. and the selected maximum temperature employed is dependent upon the extent of chlorination desired.

Inasmuch as the boiling point of the initial charge material has been raised due to the introduction of chlorine, it is generally feasible to maintain atmospheric pressures in the chlorination vessel without the use of a reflux conldenser even though the boiling range of the starting material extends below the temperatures reached during the latter stages of chlorination. It has been found in general that if the chlorination is to be effected over a reasonable period of time. it should not be continued beyond the point where the mixture contains between about 65 and 75 per cent chlorine by weight. On the other hand, the advantages of the invention are not fully realized unless the chlorination is continued until the mixture contains in the order of' at least 50 per cent chlorine. Depending upon the type of charge material and extent of chlorination, the chlorination product may be a viscous liquid or a waxlike solid which generally has a reddish color.

As discussed above, the process has preferably been carried out under atmospheric pressure because the use of such pressure has been found to result in satisfactory chlorinated materials. However, the invention is not limited to the use of atmospheric pressures; for example, higher pressures are equally operable and may be used if desired. With regard to the point at which it is desirable to subject the mixture to treatment with a solid adsorbent, it is preferred to do this only after as great an amount of chlorine has been absorbed as can be done effectively under the conditions. Nevertheless, since the adverse effects that develop in the mixture occur in the very early stages of the chlorination, satisfactory results are obtained by carrying out the initial chlorination to a relatively small extent, forexample to a point substantially short of that where darkening and coloring of the mixture has proceeded to the extent characteristic of maximum initial chlorination.

The time required for effective chlorination to a high chlorine content will vary depending upon the nature of the charge material. the rate of introduction of chlorine, the efficiency of the apparatus, and other factors. We have found that when a light liquid petroleum fraction is chlorinated in the ilrst stage to substantially the maximum extent possible in that stage and the overall chlorination is continued until the mixture contains about 70 per cent chlorine, the entire process will usually require about 45 to 50 hours when the chlorination is interrupted, and about 30 to 45 hours when carried out continuously,

In order that the invention may be understood more fully, reference should be had to the follow# ing specific examples.

Example I 500 parts by weight of Stoddard Solvent. a petroleum fraction boiling within the rangeof about 310 to 410 F. at atmospheric pressure and being obtained by distillation from a paraffinic crude oil, were placed in a narrow glass vessel. Disposed about this vessel were four elongated light sources emitting active light rays. The vessel was positioned above a heater, and was provided with a diifusion device for the 'l'ntroduction of chlorine. A conduit connected the upper end of the vessel with an atmospheric pressure reflux condenser.

Chlorine was introduced'lnto this vessel over a period of 15 hours in three increments of about 5 hours each on three successive days. During most of this period the chlorine was introduced at a rate such that a very small amount of unreacted chlorine passed through the vessel. 'Ihe exothermic chlorination reaction caused the temperature to rise to about C. but the rate ol This mixture was then agitated with per cent. by weight. of the mixture, of ilnely divided Super Fiitrol, and was then illtered. A clear, very slightly colored product, was obtained. This product was then recharged to the ehlorinating vessel. The chlorination was continued over a period oi about 32 hours (in ilve successive daily periods of about six hours each). During most oi y this chlorination periodthe temperature of the mixture was maintained ateirom about 130 to 150 C. At the end of this period the chlorine content of the mixture was '10.5 per cent by weight ci the mixture. The mixture at this stage in the process was a clear red viscous oil. It was a valuable product as it could Lbe used as a raw material for the production o! heavily fluorinated compounds. Such iluorinatedcompounds lmay be used as special lubricants.

A portion of the chlorinated mixture prepared as described was returned to the chlorination vessel and the chlorination was continued for an additional 12% hours while maintaining the temperature at about 170y C., to produce as a product a red, waxy material, solid at ordinary temperatures. The material contained 74.75 per cent chlorine by analysis.

. Example 1I Y 180 parts by weight of a mineral seal oil, a lubricating oil traction of a Mid-Continent crude and boiling within the range of about 520 to 615 F. at atmospheric pressure, were introduced into a chlorinating vessel such as described in Example I. Chlorine was passed through the oil at a rate such as to maintain an excess o! chlorine over a period of about 221/2 hours distributed over four days. During substantially all of this period the temperature was maintained above about 70 C. and did not riseabove about 125i' C. Toward the end ot the period the reaction product was, at room temperature, an extremely viscous, dark red liquid. 'I'he product had gained 266 parts in weight, indicating a chlorine content oi about 60 per cent. Since the product was too viscous at room temperature to permit illtering from an absorption agent, it was diluted with about4100 parts of CCl4v and then agitated with l0 per cent oi its weight oi' ."Super-Filtrol" for about minutes at about 60 F. and then illtered. The filtered solution was recharged to the chlorination vessel and the CCI; was removed by passing an excess oi chlorine through the solution heated to a temperature within the range of about 60 to about 80 C. The introduction oi chlorine in excess was continued fory 15% hours at a temperature of about 150 to 160 C. At the end of this time the rate of chlorine absorption was rapidly decreasing and the introduction of chlorine was discontinued. The product showed a gain in weight over the original mineral seal oil of 318.5 parts, had a chlorine content of 66.8 per cent, and was a dark red solid.

Another chlorination operation was carried out under conditions similar to those described in Example 1I except thaty the step c! contacting the 6 partially chlorinated hydrocarbon mixture with Super Filtrol was omitted. vAt the end ot a total of 40% hours o!k ,the mixture with chlorine a black material had4 s collected in the mixture. indicating thatthe product formed was decomposing and therefore the introduction oi chlorine was stopped. i The net gain in weight was only225 parts. However, because considerable material was; lost due in decomposition/tire chlorine content oi the product was 62.5 per cent. This chlorination-product was ablacksemi-solid. 1 Y,

It will be understood that the foregoing examples are merely illustrative ofthe invention.

the chlorination o! others ot the types of `hydrocarbon mixtures previously mentioned.` Also, various changes may be made in the procedures. For example, the ratek oi introduction of chlorine in the initial stage may beincreased without excessive temperature rise provided the mixture is cooled; for example, by indirectV heat exchange. `Also, the initial chlorination may be moderated by using a diluent such as hydrogen chloride or carbon dioxide. With respect to the temperatures employed in the examples and those previously discussed, it will be understood that kthe invention is not limited to the use of speciilc temperatures as in general the temperatures employed in conventional .chlorinations may be used. We have found, however, that when the temperatures referred to are employed the process yields good products in a simple manner.

The advantages of the invention may be obtained in other ways. Thus, instead'ot proceeding as described-subjecting a hydrocarbon mixture in succession to a nrst stage oi chlorination, to treatment with an adsorbent. and then to a second stage of chlorination-the process may be carried out by circulating the hydrocarbon mixture downwardly through the chlorination vessel in contact with upwardly rising chlorine gas, then passing the partiallychlorinated mixture from the bottom oi the chlorination vessel throughY a body oi adsorbent and returning the treated mixture to the top oi the vessel. When operating in this way, it is not necessary to continue the circulation of the hydrocarbon mixture after the chlorine content of the mixture has reached about 30 to 45 per cent by weight, as e of the mixture through the adsorbent in the early stages is sufficient to condition the mixture for accepting chlorine until the desired amount of chlorine has been added.

The invention may also be practiced in a continuous manner. In order that this method o! operation may be easily understood. reference should be had to the accompanying drawing in which the single ilgure is a tic illusso tration, with parts in section, of equipment employed in this embodiment.

Referring to the drawing,l the hydrocarbon mixture to be subjected tochlorination, in this case a kerosene fraction of petroleum boiling from 05 about 500 to 600 F., is introduced through line i into nrst stage chlorination tower 2 and caused to now downwardly through this tower. Tower 2 is provided with means such as trays 3 for insuring intimate contact between the hydrocarbon 70 mixture and the chlorine gas. There is positioned between each pair of trays a source of active light rays shown as elongated light tubes l, and between every other pair lof trays heat exchange coils I. Chlorine gas is introduced into the tower 'Isthrcughlinetandgasdiiiusiondevicehshcwb The procedures .described may be employed for.

as a'perforated circular tube. The chlorine passes upwardly through tower 2 in intimate contact with the descending hydrocarbon mixture and accomplishes the desired ilrst stage chlorination. Unreacted chlorine and hydrogen chloride formed in the reaction are removed from tower 2 through line 3. Additional hydrogen chloride and chlorine gas are introduced at an intermediate point in tower 2 through line 3. This hydrogen chloride and chlorine are'recycled from a second stage chlorination as will presently be described.

The conditiom maintained in the irst stage chlorination tower are preferably substantially the same as those described in Example I above. Thus the pressure is preferably about atmospheric and the temperature between about 80 and 110 C. The rate of flow of the hydrocarbon mixture through the tower and the rate of introduction of chlorine are preferably such as to produce at the bottom of the tower a hydrocarbon mixture containing 30 to 45 per cent chlorine. It is preferred to maintain a temperature gradient from the top to the bottom of this tower of at least 30 C.; e. g., varying from about 80 to 110 C. Such a gradient is insured by heat exchange coils 5. Thus, in the upper section of the tower when chlorinating reactive hydrocarbons the coils are used for cooling the mixture, and in lower section containing the partially chlorinated and therefore less reactive compounds the coils are used for heating the mixture.

This partially chlorinated mixture is removed from tower 2 through line I0 provided with a pump I| and leading tov a cooling zone I2 where the temperature of the chlorinated mixture may be reduced, for example to about 20 to 30 C. The cooled mixture is then passed through line I3 and through either valved line I4 or valved line I5 leading respectively to an adsorption tower I6 and a similar tower I1. These adsorption towers contain an activated clay such as Super Filtrol" in the form of 16 to 8 mesh granules. The towers are used alternately, one being regenerated while the other is in use.

The treated partially chlorinated mixture is removed either through valved line I8 or I9, depending upon which treating tower was employed, which are connected with line 20 leading to second stage chlorinating tower 2 I. It is usually desirable to heat the hydrocarbonmixture before introducing it into tower 2|. To accomplish this the mixture is passed through valved line 22 and heater 23 and returned to line 20 through valved line 24. The temperature of the mixture is preferably raised in this heater to about 90 to 110 C. Tower 2| is constructed similarly to tower 2 previously described. Thus it is provided with trays 21, sources of light 29, and with heat exchange coils 3|. Chlorine gas is introduced through valved line 32 leading to a diiusion device 33. In this tower the downwardly flowing partially chlorinated hydrocarbon mixture is contacted with chlorine gas in countercurrent fashion at a pressure which may be substantially atmospheric and at elevated temperature conditions. Heat is supplied to the tower through the heating coils so that the temperature at the bottom of the tower is the maximum desired for effective chlorination; for example, a temperature within the range of about 150 to 200 C. As indicated above, the temperature of the hydrocarbons entering this tower may be substantially atmospheric temperature or it may be a temperature of about 90 to 110 C. In any case, it is preferred to control the operation so 8 that there is a temperature gradient from the top to the bottom of the tower of from about 50 to 100 C.

Since a high degree of chlorination is accomplished in tower 2 I, chlorine is introduced through line 32 in substantial excess of that taken up by the mixture. The excess chlorine together with hydrogen chloride formed in the reaction is removed through line 34. A part of this mixture is passed to a. recovery system, not shown, through valved line 36, and the remainder is passed through valved line 3 leading to first stage chlorination tower 2 as previously described. The chlorinated mixture is removed from the bottom of tower 2| through a line 31 provided with a pump 38 and is passed into a fractionating tower 33.

In the fractionatlng tower the chlorinated mixture is separated into a heavily chlorinated fraction and a less-heavily chlorinated fraction. As is well known, in the chlorination of hydrocarbons, the addition of chlorine goes unevenly so that a part of the mixture is more heavily chlorinated than another part. The partially chlorinated hydrocarbons are passed overhead from the fractionating tower through valved line Il to a condenser l2 and are returned to second stage chlorination tower 2| through valved line I3. The desired heavily chlorinated product is removed from the fractionating tower through valved line In many cases where the presence of partially chlorinated hydrocarbons in the final product is not undesirable, the use of the fractionating tower may be dispensed with.

When chlorinating a heavy hydrocarbon oil by the 'continuousocess described, the partially chlorinated mixture leaving tower 2 is preferably thinned before contact with the adsorbent. with an unreactive solvent such as CCh which is vaporized and removed in the second stage chlorination tower.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, but only such limitation should be imposed as are indicated inthe appended claims.

We claim:

l. The process of chlorinating a hydrocarbon to a high chlorine content which comprises reacting the hydrocarbon in liquid phase with chlorine under irradiation by actinic light rays to accomplish substantial chlorination, removing the resulting chlorinated hydrocarbon from contact with free chlorine, then flowing the resulting -chlorinated hydrocarbon through an amount of an adsorbent in active condition thereby removing from said resulting chlorinated hydrocarbon more easily adsorbed bodies formed in said chlorination, and then reacting the treated product free from said more easily adsorbed bodies with chlorine under irradiation by actinic light rays to accomplish additional chlorination.

2. The process of chlorinating a hydrocarbon mixture to a high chlorine content which comprises reacting the `mixture in liquid phase with chlorine under irradiation by actinic light rays until the rate of acceptance of chlorine by the hydrocarbon mixture has substantially decreased, removing the resulting chlorinated hydrocarbon mixture from contact with free chlorine, then flowing the resulting chlorinated hydrocarbon mixture through an amount of an adsorbent in active condition thereby removing from said resulting chlorinated hydrocarbon mixture more easily adsorbed bodies formed in said chlorinathen iiowing the resulting chlorinated petroleum.

fraction through an amount of an adsorbent in active condition thereby removing from said resulting chlorinated petroleum fraction more easily adsorbed bodies formed in said chlorination, and then reacting the treated product free from said more easily adsorbed bodies with chlorine under irradiation by actinic light rays to accomplish additional chlorination.

4. The process of chlorinating a liquid petroleum fraction to a high chlorine content which comprises reacting the petroleum fraction in liquid phase with chlorine under irradiation by actinic light rays until the rate of acceptance of chlorine by the petroleum fraction has substantially decreased, removing the resulting chlorinated petroleum fraction from contact with free chlorine, then flowing the resulting chlorinated petroleum fraction through an amount of an adsorbent in active condition thereby removing from said resulting chlorinnated petroleum fraction more easily adsorbed bodies formed in said chlorination, and then reacting the treated product free from said more easily adsorbed bodies with chlorine under irradiation by actinic light rays to accomplish additional chlorination.-

5. A continuous process of chlorinating a hydrocarbon mixture which comprises, in a first chlorination zone, owing the mixture downwardly in liquid phase in intimate admixture with an upwardly ilowing stream of chlorine gas under conditions including irradiation by actinic light rays until the rate of acceptance of chlorine by the hydrocarbon mixture has substantially decreased, removing the resulting partially chlorinated hydrocarbon mixture from contact with free chlorine, then flowing the resulting partially chlorinated hydrocarbon mixture through an amount of an adsorbent in active condition thereby removing from said resulting partially chlorinated hydrocarbon mixture more easily adsorbed bodies formed in said chlorination to produce a treated mixture, nowing the treated mixture into a second chlorination zone. owing said mixture downwardly in liquid phase in intimate admixture with an upwardly flowing stream of chlorine gas in said second chlorination zone under conditions including irradiation by actinic light rays to accomplish additional chlorination, fractionatlns the resulting chlorinated product into a heavily chlorinated fraction and a less-heavily chlorinated fraction, and returning the less-heavily f chlorinated fraction to intimate contact with chlorine in the second chlorination zone.

6. A process in accordance with claim 5 in which a temperature gradient is maintained over the nrst and second chlorination zones. the temperature at the top of each oir said zones being lower than temperature at the bottom of each of laid zones.

'haproceinaccordancewithclaimin which the hydrocarbon mixture is a light liquid petroleum fraction.

8. The process of chlorinating a liquid petroleum fraction to a high chlorine content which comprises reacting the petroleum fraction in liquid phase with chlorine under irradiation by actinic light rays at a temperature within the range of about to about 110 C. until the rate of acceptance of chlorine by the petroleum fraction has substantially decreased, removing the resulting chlorinated petroleum fraction from contact with free chlorine, then flowing the resulting chlorinated petroleum fraction through anvk amount of an adsorbent in active condition thereby removing from said resulting chlorinated petroleum fraction more easily adsorbed bodies formed `insaid chlorination, and then admixing the treated product free from said more easily adsorbed bodies with chlorine under irradiation by actinic light rays at a temperature of about to about 170 C. to accomplish additional chlorination. A

9. The process of chlorinating a hydrocarbon mixture to a high chlorine content which comprises, in a rst chlorination zone, continuously .flowing the mixture downwardly in liquid phase in intimate admxture with an upwardly flowing stream of chlorine gas under conditions including irradiation by actinic light rays to accomplish substantial but incomplete chlorination, iiowing ,the resulting partially chlorinated hydrocarbon mixture from the bottom of said tlrst chlorination zone through the rst of two adsorption zones containing a solid adsorbent in active condition thereby removing from said resulting partially chlorinated hydrocarbon mixture more easily adsorbed bodies formed in said chlorination to produce a treated mixture, nowing the treated mixture into a secondchlorination zone, flowing said mixture downwardly in liquid phase in intimate admixture with an upwardly flowing stream of chlorine gas in said second chlorination zone under conditions including irradiation by actinic light rays to accomplish additional chlorination, continuing owing the partially chlorinated hydrocarbon mixture from said first chlorination zone through said adsorption zone until the adsorbent becomes inactive due to adsorption of the more easily adsorbed bodies formed in the chlorination in said rst chlorination zone. then flowing the partially chlorinated hydrocarbon mixture from the bottom of said rst chlorination zone through the second adsorption zone containing a solid adsorbent in active condition, and regenerating the inactive solid adsorbent in the rst adsorption zone.

EARL L. HUMPHREY. EDWARD MITCHELL.

REFERENCES CITED The following references are of record in the ille 01' this patent:

UNITED STATES PATENTS Number Name Date 1,432,761 Koch Oct. 24, 1922 1,623,018 Cross Mar. 29, 1927 2,015,044 Teichmann et al. Sept. 17, 1935 2,130,952 Hardie et a1 Sept. 20, 1938 2,242,226 Bley May 20, 1941 2,403,179 Hull et al July 2, 1946 OTHER REFERENCES- Shile et al.: Chemical Abstracts, vol. 28. (1934) p. 4886. 

1. THE PROCESS OF CHLORINATING A HYDROCARBON TO A HIGH CHLORINE CONTENT WHICH COMPRISES REATING THE HYDROCARBON IN LIQUID PHASE WITH CHLORINE UNDER IRRADIATION BY ACTINIC LIGHT RAYS TO ACCOMPLISH SUBSTANTIAL CHLORINATION, REMOVING THE RESULTING CHLORINATED HYDROCARBON FROM CONTACT WITH FREE CHLORINE, THEN FLOWING THE RESULTING CHLORINATED HYDROCARBON THROUGH AN AMOUNT OF AN ADSORBENT IN ACTIVE CONDITION THEREBY REMOVING FROM SAID RESULTING CHLORINATED HYDROCARBON MORE EASILY ADSORBED BODIES FORMED IN SADI CHLORINATION, AND THEN REACTING THE TREATED PRODUCT FREE FROM SAID MORE EASILY ADSORBED BODIES WITH CHLORINE UNDER IRRADIATION BY ACTINIC LIGHT RAYS TO ACCOMPLISH ADDITIONAL CHLORINATION. 